Sonar fix: restore thread interrupted state

commons-math-examples/examples-sofm/tsp/src/main/java/org/apache/commons/math4/examples/sofm/tsp/TravellingSalesmanSolver.java

@@ -124,6 +124,8 @@ public final class TravellingSalesmanSolver {
                 f.get();
             }
         } catch (InterruptedException | ExecutionException e) {
+            // Restore interrupted state...
+            Thread.currentThread().interrupt();
             throw new RuntimeException(e);
         }
         // Terminate all threads.